Strike CNC (My first CNC router)

[JAZZCNC]

Oh dear is it *that* bad?

I knew there were compromises made for that price but I figured for wood it'd be fine.

I'm a big boy and its a router not my first born so please don't feel any need to censor yourself.

Ok first I appologize, I made it sound worse than was intended.! I've got a canny knack of pointing out or saying truths "some" Dont want to hear.!! (Mainly the ones selling the machine) But seen as your ok with it then I'll point out the things I think are not Ideal.
First So to be clear for others " THIS IS JUST MY OPINION BASED ON MY KNOWLEDGE" Others will have theres' but this is mine and I've been invited to give it.!!. . .So get stuffed if you dont like it.!!:dance:

Z Axis:. . .Yes I agree with John S, Gary unsupported round rail is ok for short Z Axis. . . But this hisn't short, It's quite long.!
The over hang from bearings to tool tip looks to be a far bit creating a long-ish lever, also the front and rear plate don't look very thick. The other thing is the rear plate length and the amount of unsupported over hang from Y axis bearings, again too much without support IMO. Yes this will be ok for the little Kress but if you want to upgrade to water cooled or larger spindle then I think it will show it's weakness. . . It will certainly restrict the depth of cut(DOC) and feed rates (Fr), even in wood.

Tho it's not easy to see from the pics I get the feeling the Y Axis top gantry cross brace is just a piece of Aluminium plate with the rails bolted onto to it for support.? Say this because cant see any slots that would be present if it was wide profile.!! . . . If so then with that heigh/width gantry combo at this width of machine then it needs bracing up more IMO.
Don't like the ratio between gantry height and gantry side width, the bearing spacing hisn't very much. Yes it's driven from both sides but the height and width don't gel nice and if like I belive the gantry cross piece is just Ali plate with no bracing and just relying on the rails for support then flex will show when cutting hard or deep.!!. . Again restricting DOC & FR.

The frame under the bed hisn't supported enough with just one central support for this wide a machine IMO.

Not a major issue but not keen on them little nema23 motors spinning 25mm ballscrews, they are going to be working over time with the extra inertia of 25mm ballscrews.!

Please don't get me wrong I'm not saying the machine is rubbish because it's not, but again "IMO" It does have potential for issue's in some area's.!! And even thou you are only planning on cutting wood, there's cutting wood and then theres cutting wood with correct DOC & FR's and this is when any weak area's show them selfs.!!!

On another note I also think the bullk of the cost of this machine would have been the Cabinet enclosure.??

Like Routercnc I would be interested to know the spec of the drives control box etc.! . . . Also the price if your up for sharing.??

Hope you have good fun when it arrives and I'm sure you'll enjoy it..

[Shinobiwan]

Ok first I appologize, I made it sound worse than was intended.! I've got a canny knack of pointing out or saying truths "some" Dont want to hear.!! (Mainly the ones selling the machine) But seen as your ok with it then I'll point out the things I think are not Ideal.

No problem, I wish I'd known about this place back when I first started looking around. Nothing wrong with a frank opinion, I'd rather have that than the marketing speak!

From my limited knowledge I can see your concerns about some of the decisions taken with the construction but whether this negatively affects the parts I intend to produce will only be realised once I start cutting. I think your right that I'll have to dial back the speeds significantly. I've been told rapids of 5000mm/m are to be expected but cutting will reduce this greatly and I imagine 1500 upto possibly 2000mm/m with a 1/4" DOC in MDF will be about the limit. I'm more concerned about acceleration because I'll be doing a lot of detail work where this is more important than traverse speeds. Wondering how much things will jerk around with higher settings, probably quite a lot by the sounds of it sadly.

Tho it's not easy to see from the pics I get the feeling the Y Axis top gantry cross brace is just a piece of Aluminium plate with the rails bolted onto to it for support.? Say this because cant see any slots that would be present if it was wide profile.!! . . . If so then with that heigh/width gantry combo at this width of machine then it needs bracing up more IMO.
Don't like the ratio between gantry height and gantry side width, the bearing spacing hisn't very much. Yes it's driven from both sides but the height and width don't gel nice and if like I belive the gantry cross piece is just Ali plate with no bracing and just relying on the rails for support then flex will show when cutting hard or deep.!!. . Again restricting DOC & FR.

It does look like alu plate that forms the gantry but its alu extrusion. I'm not sure about the exact dimensions but it looked like about 160mm x 30mm or possibly 160x20mm.

The frame under the bed hisn't supported enough with just one central support for this wide a machine IMO.

This was a concern of mine in recent days since I started looking at some of the DIY builds on here - much more substantial beds. I can't see an easy way of bracing it more thoroughly though, especially in the direction parallel to the gantry, because the ball screws are in the way make a decent and useful cross section of bracing impossible to fit in there.

Not a major issue but not keen on them little nema23 motors spinning 25mm ballscrews, they are going to be working over time with the extra inertia of 25mm ballscrews.!

I was led to believe these are nema28 on the x and y with 4Nm rating. However when I do a good search for nema28 I get nothing. Only nema23 and 34 return useful results. Unsure now.

On another note I also think the bullk of the cost of this machine would have been the Cabinet enclosure.??

The enclosure was £600 extra so nearly an 1/8th of the price.

Like Routercnc I would be interested to know the spec of the drives control box etc.! . . . Also the price if your up for sharing.??

I feel some what stupid because I have no idea about the electronics aside from the specs I was given(these are in the original post). The machine was the first of its kind with the enclosure so I agreed to have them take some pictures for marketing purposes and got it cheaper. They're selling the same machine with hiwin rails all around (mine is only on the Y) and possibly some more upgrades including the electronics for £6999.

Hope you have good fun when it arrives and I'm sure you'll enjoy it..

I'm sure I will and thanks.

[Jonathan]

I was going to post something similar to what Jazz has just posted about this machine, but there's no point now as he's said it all really.

Hopefully the 4nm motors are these:

http://www.cnc4you.co.uk/index.php?r...&product_id=70

So strictly speaking Nema 24. They're quite promising as they have a low inductance for their size, though I've never tried them. It's such a mismatched system. Instead of going for a higher lead ballscrew for X (i.e. RM1610 like they used on Y, or RM2010) to prevent whipping they've used a 25mm ballscrew then stuck bigger motors on to try and compensate, but it will still be nowhere near the performance (especially acceleration) you could get with 3Nm motors and a smaller diameter screw. 5m/min is adequate as the machine probably isn't rigid enough to cut faster than that.

£600 sounds a lot to add for an enclosure, though the price is understandable given the use of aluminium extrusion. Why not just make it out of wood, e.g pine or if they have a big enough machine cut the enclosure out of plywood sheet? Should be much cheaper.

You could add more braces to the bed parallel to the X-axis without interfering with the ball-screws. Without that you may see the bed bend away from the tool when it plunges down. Plunging with the tool something to avoid anyway (unless it's a drill!) but not always possible.

[JAZZCNC]

It does look like alu plate that forms the gantry but its alu extrusion. I'm not sure about the exact dimensions but it looked like about 160mm x 30mm or possibly 160x20mm.

Ah ok slightly better than feared thou at this width extra bracing would be my prefered choice.

This was a concern of mine in recent days since I started looking at some of the DIY builds on here - much more substantial beds. I can't see an easy way of bracing it more thoroughly though, especially in the direction parallel to the gantry, because the ball screws are in the way make a decent and useful cross section of bracing impossible to fit in there.

I would run 2 piece's parallel with the screws close as possible, positioned vertical like the side rails. I would also change the centre one to the same position then take staggered cross supports between each. If your not sure what I mean just ask and I'll draw it for you.

The enclosure was £600 extra so nearly an 1/8th of the price.

They're selling the same machine with hiwin rails all around (mine is only on the Y) and possibly some more upgrades including the electronics for £6999.

£600 is very cheap for the enclosure like as been said but to be honest for 7K I'd want far more for my money than this machine offers. I'm self employed so know exactly how hard times are at the moment but to be honest at 7K there making VERY good profit.!!

[Shinobiwan]

I would run 2 piece's parallel with the screws close as possible, positioned vertical like the side rails. I would also change the centre one to the same position then take staggered cross supports between each. If your not sure what I mean just ask and I'll draw it for you.

A good suggestion and this is something I will very likely do.

[Strike CNC]

[QUOTE=JAZZCNC;27824]Ah ok slightly better than feared thou at this width extra bracing would be my prefered choice.

Hi the gantry back support on this model is 30x180mm heavy gauge we have several gantry options available for the customer to choose from
30x180mm
30x200mm
30x300mm
40x200mm
40x300mm
60x320mm

we also have a range of gantry uprights available
40x120mm
40x160mm
40x320mm
60x320mm
80x320mm

Our machines do weigh a great deal even our standard models are very heavy which is why they are so rigid no additional bracing is needed on this model they really are solid, but i do understand your concern as you just cannot see from the pictures but once you see them in the flesh "so to speak" its only then you get some idea of how rigid they are customers are always surprised by the weight of the machines.
As the customer you can virtually design your own custom CNC we us by choosing from our range of components to get a truly customised CNC router to your own spec. We have supplied a customised M series of the PRO 660x660 CNC to 2 engineering firms to replace there small CNC mills once they seen what our metal range of CNC routers can produce & for a fraction of the price of a CNC mill there sold ,our 3 phase 5HP & 7HP water cooled spindles chew through aluminium like butter & you can high speed machine with them too cutting production runs down significantly ,one client has been running his older one for the past 26 months machining aluminium all day 6 days a week & its still going strong the customer has since purchased another unit this time with full enclosure i do have permission from the company to use pictures of the components they machine with the CNC if anyone's interested seeing them we are currently archiving a selection of customers work to be placed on our new website the only draw back with the M series of machines is they are incredibly heavy even the small models are obscenely heavy to give you a idea 4 people cannot even pick up the small STK M series & this only has a 660x660 cutting bed & stands 1700mm tall
best wishes
all the best
best wishes

[JAZZCNC]

[QUOTE=Strike CNC;27874]

Our machines do weigh a great deal even our standard models are very heavy which is why they are so rigid no additional bracing is needed on this model they really are solid, but i do understand your concern as you just cannot see from the pictures but once you see them in the flesh "so to speak" its only then you get some idea of how rigid they are customers are always surprised by the weight of the machines.

Ok first off PLEASE PLEASE don't under estimate the knowledge and expereince of some of the people you are speaking to here on the forum. I know exactly the weight and strength of the materials you use because I use them also.! . . BUT . . . There's a difference between material weight and mechanical stength.!
My reference to bracing had nothing to do with the material weight or choice and everything to do with the structural bracing.! . . . Which IMO at this size and proportions it's lacking.!

I agree 110% regards building the machine to do an intended job. . BUT . . in this case while YES it will fullfill the "Brief" it could have been so much better for so little more.!! . . Or better put you spoilt the broth to save a pinch more salt.!!

Given the full picture regards componets then with a bit more bracing (Esp the BED) and a REAL Z Axis then this machine could handle most jobs and materials upto Aluminium with good usable DOC.! . . .As it is now it will always be lacking.!!

My view and feelings regards machines built in this manner with these materials is that they are built purely with ease of build to extract maximum profit using off the shelf products. This often leads to comprimise, whether that be finacial or strength, they generaly lack in one or the other.!

IMO given the fact that at £3860(taking away the £600 for the enclosure) and the very fact that building this machine how you do requires very little equipment other than a decent drill press and could be built in just a few days then you are still making very good profit. Certainly enough to give a better Z axis using at least supported round rails and couple more piece's of profile for the bed.!!. . . . This would make the machine capable of so much more.!!

I wish you every success and please don't take my comments as a personal attack,.they are observations and MY OPINOINS gained from my experience building machines for my self and others and which I was invited to give (And feel should be said for the sake of others). I fully understand the need for profit being in business 0ver 25 years my self but some times saving that "Pinch of salt" really does spoil the soup IMO..!!!

[Robin Hewitt]

Personally I like a lot of dead weight, but that's just me. It looks wonderful, if I needed a router I'd buy one

The proof of the pudding will be in the eating. Do we get a movie?

[JAZZCNC]

Personally I like a lot of dead weight, but that's just me.

Yep me too Robin if it's used correctly. . . . As we know Mass can be your friend. It also weddles the weak bits out pritty quick.!!

Also forgot to say LOVE THE SPEAKERS. .

[Shinobiwan]

The proof of the pudding will be in the eating. Do we get a movie?

That's the plan once I get it up and running. There's a couple of jobs to do before that can happen:

• Dust extraction. Gotta cut a hole the top of the enclosure and plumb this in.
• The doors at the rear need modifying as I changed where the machine was going at the last minute and didn't want to hold up the machine any longer. Without the mod its difficult to open the doors because of limited space.
• I bought one of the 3HP Chinese water cooled spindle & vfd packages off ebay and it arrived yesterday so now I have the dilemma of choosing whether to get up and running quickly with the Kress or wait for some mounts and install the spindle/vfd combo.